Mechanical fire detection alarm device



United States Patent lll13,529,567

Primary Examiner-Louis J. Capozi Altorney-Miketta, Glenny, Poms and Smith ABSTRACT: A fire detection alarm device having a biased pivotally mounted hammer actuating member movable to strike a sound or hammer pin to drive the sound pin against a cover, the sound pin being freely slidable along its long axis. The hammer actuating member carries an inertia member limitedly movable relative thereto for continued movement of the inertia member after the pin has been struck to disengage a latch member from a gear drive system. The gear drive system returns the hammer actuator member to its start position of a hammer actuating stroke, the gear means including an escapement wheel normally restrained against rotation and releasable by trigger means either manually or thermo-responsibly actuated. A visible signaling device is positively displayed when unwinding commences of a spring motor which drives the escanement wheel.

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5402/0 GEH. .5M/EV mezza@ Patented Sept. 22, 1970 Sheet ,MM5 J f w@ W EL@ BACKGROUND OF THE INVENTION Fire detection alarm devices have been proposed which were either electrically energized or mechanically energized. In the event of a fire under some conditions an electrically energized alarm device might not sound an alarm because of an electrical power failure. Therefore, mechanical alarm devices are highly desirable because they are not dependent upon electrical power.

Prior proposed mechanical alarm devices have included numerous arrangements of spring motors, gear trains, escapement means, and fuse means which upon melting released certain elements of the prior proposed alarm devices to cause the alarm to commence ringing. Such prior proposed devices included several disadvantages, such as, ringing for too short a time (2-3 minutes), unwinding and ringing the alarm at a nonuniform rate, employing fuse means which were difficult to replace after melting, the reliance in some proposed constructions upon the fuse element to hold the alarm in condition for unwinding, and the sometimes awkward arrangement of winding a mechanical alarm. Further, some of such prior devices were not capable of being mounted in any position on a wall or a ceiling but required a specific orientation of the alarm device with respect to gravitational forces for proper operation of the device. In such devices where fuse elements were melted to set off the alarm, manual testing of the device to determine its operability was often difficult and required the replacement ofa fuse element.

The present invention contemplates a novel mechanical fire detection alarm device which obviates many of the disadvantages of the prior proposed devices and provides an alarm device which is virtually fool proof in operation. The present invention contemplates an outer decorative housing within which is virtually concealed an inner dust-tight sealed housing which contains the alarm mechanism. A trigger mechanism for a releasable latch to release a spring biased hammer actuating member holds the actuating member in cocked position and is releasable from such cocked position by a thermoresponsive means such as a bimetallic disc or a manual uncocking button. Return of the hammer actuating member to the beginning of a hammer stroke is accomplished by a wound spring motor which drives an escapement wheel which has teeth successively engagable by a projection on the hammer actuating member. The present invention also contemplates an alarm device wherein a visible signal flag is projected beyond the periphery of the outer housing upon the initiation of unwinding of the spring motor so that a partially unwound condition of the alarm is immediately signaled.

It is therefore a primary object of the present invention to disclose and provide a novel fire detection alarm structure which embodies novel features of operation and arrangement of sounding pin, hammer actuating member, and spring motor.

An object of the invention is to'disclose and provide a mechanical fire detection alarm device utilizing a nonmelting fuse means such as a thermo-responsive bimetallic member.

A further object of the invention is to disclose and provide an alarm device in which a trigger means is associated in novel manner with a thermo-responsive bimetallic means for actuating the device at a selected temperature.

Still another object of the invention is to disclose and provide a mechanical alarm device including novel means for operation of a hammer actuating member and its connection to a trigger means and to a spring driven escapement means.

A still further object of the invention is to disclose and provide a fire detection alarm device which may be readily tested and which may be readily placed into operative condition after it has sounded an alarm without replacement of any parts.

The invention contemplates a mechanical fire detection alarm device which is compact, contains its own mechanical signal for an extended time period, is reliable, is capable of mounting in virtually any position, and produces a sound which is in the order of to 100 decibels.

Various other advantages and objects of the present invention will be readily apparent from the following description of the drawings in which an exemplary embodiment of the invention is shown.

IN THE DRAWINGS FIG. l is a perspective view of an alarm device embodying this invention and illustrating attachment of the device to a supporting surface.

FIG. 2 is a side elevational view of the alarm device assembled with the mounting means shown in FIG. 1, the view being partly in section, the section being taken in a vertical plane bisecting the mounting means.

FIG. 3 is a fragmentary back view of the device taken in the plane indicated by line III-III of FIG. 2.

FIG. 4 is an enlarged sectional view taken in the plane indicated by line IV-IV of FIG. 2 and showing relative position of parts just after release from a locked start position.

FIG. 5 is a fragmentary view similar to FIG. 4 showing relative position of parts at one end of an oscillatory stroke, the phantom lines indicating part positions at the other end of the stroke.

FIG. 6 is a sectional view taken in the planes indicated by line VI-VI of FIG. 4.

FIG. 7 is an enlarged fragmentary sectional view of a back portion of the device and taken in the planes indicated by lines VII-VII of FIG. 4.

FIG. 8 is a fragmentary sectional view taken in the plane indicated byline VIII-VIII of FIG. 7.

FIG. 9 is a fragmentary view similar to FIG. 4 illustrating the position of parts at a locked start position.

FIG. 10 is a fragmentary sectional view taken in the plane similar to FIG. 4 but with certain parts removed to better illustrate the visible signal means.

FIG. I1 is a perspective view of the hammer actuator member shown-in FIG. 4.

FIG. 12 is a perspective view of an inertia part associated with actuator member of FIG. 11.

FIG. 13 is an enlarged sectional view showing a trigger and thermal-responsive means for starting the alarm device.

FIG. 14 is an enlarged fragmentary sectional view of a portion of FIG. I3.

FIG. 15 is a perspective view of a part of the trigger means.

FIG. I6 is a perspective view of a part of the escapement release or latch mechanism.

In FIG. 1 a temperature responsive mechanical sound alarm device embodying this invention is generally indicated at 20. Generally speaking, device 20 includes a housing means 2l attachable to a suitable supporting surface by mounting means 22. Within housing 2l may be provided a spring motor means 23 (FIG. 7) which may drive through a system of gears an escapement means 24 (FIG. 4) a sound hammer actuating means generally indicated at 25 for striking a sound hammer pin 26. A trigger means generally indicated at 28 (FIGS. I3, 14) includes a thermally responsive and a manually actuatable trigger means. A visual signal means 29 indicates immediately partial unwound condition of the alarm device. A latch means 72 normally engaging the escapement means is releasable by inertia means on the hammer actuating means.

In detail, housing means 21 includes an outer circular suitably frustoconically shaped outer cover 31 which encloses an inner sealed housing 32 (FIG. 6) which comprises an outwardly facing or opening base member 33 and an inner housing cover 34 of smaller but of generally the same configuration as outer cover 31 for convenient nest-like reception thereof in outer cover 31. The inner cover 34 and base member 33 may be secured and scaled along their margins in dust-tight rela- Means for mounting device 20 on a supporting wall surface such as 36 may comprise an elongated bracket 37 secured to surface 36 by a suitable headed bolt and keyhold slot means 38. Bracket 37 includes a top offset portion 39 having an in verted W-shape provided with a notch 40 for reception of a headed button 42 carried by base member 33. A pair of diverging stabilizing rod-like elements 44 embrace the inverted W of offset top portion 39 for laterally and vertically stabilizing the mounting of device 20. Rods 44 also orient positively the mounting of device in a substantially upright vertical position so that device 20 will ring substantially the same length of time as if mounted horizontally.

At the bottom of bracket 37, a similar offset bottom portion 45 may also be provided with a notch 46 to receive a headed button 47 carried by the base, In this example, a ported leaftype spring 49 of flat spring metal stock may be secured to bracket 37 as at 48 to bias and lock device 20 on the mounting bracket 37 by engagement of the spring port with button 47. Release of device 20 from bracket 37 is readily accomplished by depressing the bottom end of spring leaf 49 to release the port-button contact to permit the device to be lifted out of notches 40 and 46. In this example, stabilizing elements 50 may also be provided at the lower portion of bracket 37 to laterally stabilize the device.

Within inner cover 32 and base member 33 is carried in substantially dust-proof and dirt-proof environment a spring motor means 23 for rotatably driving the gear and escapement means 24. Motor means 23 may comprise a coiled spiral spring 52 of suitable spring strength and of a suitable number of turns to provide a desired energy output for ringing the alarm device for a predetermined period of time, for example, about 7 minutes. Spring 52 may have one end 53 secured to a rotatable spring housing 54 and its other end may be secured to shaft 55. Spring housing 54 carries on one wall an internal toothed ring gear 56 which meshes with an idle gear 57 rotatably mounted on a transverse support member 59 suitably secured to the base member. Idle gear 57 has toothed meshed engagement at 60 with the hub of an escapement wheel 62 of relatively large diameter and which turns with the shaft 55 of the spring motor. The escapement wheel 62 is normally held against rotation by means later described. The shaft 55 extends rearwardly through a central recessed back portion 63 of the base.

Means for tightening spring motor 52 when latch means is in engagement with teeth on the escapement wheel 62 for holding the wheel and spring housing against rotation may comprise a square section end portion 64 on shaft 55 adapted to be engaged by a square section bore 65 of a winding key 66. The winding key 66 carries on its' inner surface a spring metal disc having a plurality of spaced inwardly directed spring lock elements 67 which engage a plurality of spaced cooperable lock ridges 68 provided on a normally stationary disc 69 carried on the base. The elements 67 are angularly disposed to permit winding of the spring motor in one direction and when such winding is completed to lock the shaft against relative rotation by engagement of lock elements 67 with ridges 68.

Means for actuating the sound hammer pin 26 by the energy stored in spring 52 and available through controlled incremental rotation of escapement wheel 62 Vmay comprise a releasable escapement latch lever 72 pivotally mounted on the base at 73 and having at its opposite end an escapement engagement or latch face 74 (FIG. 4) which contacts a leading tooth face 75 or one of a plurality of teeth on the escapement wheel 62. Lever 72 is biased into such engagement by a suitable spring 76. Spaced from the longitudinal axis of escapement lever 72 and carried by an offset portion 77 is an upstanding abutment boss 78 serving to release lever 72 from a tooth face 75 as later described.

The actuating means 25 also includes an oscillatable pivoted hammer pin striking member 80 (FIG. 11). Member 80 may be pivotally mounted from the base at 81 and may comprise a middle portion 82 and an arcuate end portion 83 provided with a depending peripheral counterweight 84. One

end of the arcuate counterweight may be provided with a depending stop pin 85 for engagement with an upstanding abutment 86 carried by the base to limit oscillation of member 80 in one direction and to determine the end of the hammer pin actuating stroke when hammer pin 26 is not assembled with inner housing (as during assembly of the device).

At the opposite end of middle portion v82 member 80 is provided with an arcuate peripheral upstanding thick section 88, said upstanding section 88 having at one end a hammer pin strike face 91 and at the other end a trigger engagement face 90A As best seen in FIG. 4 in one position of the hammer actuating means occurring just after release from the trigger means as later described, the hammer pin strike face 89 abuts as at 91 an end face 92 of sounding hammer pin 26 which is freely slidably mounted in a bore 93 provided in a boss 94 projecting inwardly from the upstanding wall of base 33.

The actuating means also includes an escapement lever release inertia member 97 (FIG. 12) of generally circular or disc configuration and having a peripheral extended portion 98. The inertia member 97 is provided with a port 99 for pivotally mounting the same on member 80 at its pivotal axis 81. The portion 98 includes a circular opening 100 which receives an upstanding boss 101 on member 80. Thus when member 80 turns in a clockwise direction and strikes pin 26 the inertia member 97 will continue to pivot about mounting 81 so that face 102 of portion 98 will strike against the boss 78 carried on lever 72 to pivot lever 72 out of engagement with the escapement wheel to release latch face 74 from a tooth face 75.

Member 80 is normally biased into clockwise movement and to the end of the hammer pin actuating stroke by a spring 104 secured to the base at one end and to a depending pin 105 carried by the hub 106 of the member 80.

Means for returning the hammer actuator member 80 to its initial start position and from the end of the pin actuating stroke as shown in FIG. 5 may comprise interfacial engagement at 107 between an escapement wheel tooth face 75 and a face on a lateral extension 108 of hub 106, the lateral extension being beneath portion 82 and carrying pin 105. As best seen in FIG. 5, the latch member 72 has been retracted from its engagement with tooth face 75. The spring motor turns the escapement wheel which, by its interfacial engagement at 107, turns the member 80 counter-clockwise until it reaches a position just beyond that shown in FIG. 9. In return movement of actuator member 80 it will be apparent that inertia member 97 is returned with actuator member 80 by interengagement of boss 101 with the opposite face of the opening 100. In FIG. 9 and at the start position of actuator member 80 the latch lever 72 has been returned by spring 76 to engage the next tooth of the escapement wheel and the contact of hub extension 108 with the escapement wheel tooth has been disengaged so that the actuator member 80 is free to commence its next hammer actuating pin stroke provided that the trigger means 28 is in release position.

Trigger means for releasing hammer actuator member 80 is indicated generally at 28 and may comprise a hub 110 (FIG. 15, 4) providing a pivotal mounting on the base at 111 and from which may extend a triangular trigger member 112 having at the vertex of base 113 and side 115, a wobble port 114 and at an extension of side 115, a trigger face 116. Pivotal movement of trigger member 112 about its hub 110 is limited by an arm 118 entending from said hub and having engagement with headed end 119 of a radially disposed manual test pin 120 carried in free sliding relationship within a bore 121 in an internal boss 122 provided on an upstanding wall 33a of the base. A stop pin 123 is carried by the base for limiting counterclockwise rotation of member 112. Member 112 is biased by a spring 124 connected to the member at 125 and to the base at 126 for biasing the trigger member 112 in a direction for engagement with trigger face 90 of the member 80. e

The function of wobble port 114 on trigger member 112 will be described in connection with the temperature responsive means 27. As seen in FIGS. 6, 13 and I4 the outer cover 31 carries a temperature responsive means 130 comprising a circular disc of bimetallic material. The disc 131 may be carried in a suitable receptacle 132 which may be mounted on cover 31 at its axial center. Means 130 includes a threaded body 133 adapted to have threaded engagement with the cover and to extend into a recess 134 in inner housing 34. Means 130 includes an axially displaceable pin 135 which has one end adjacent to the bimetallic disc 131 and which is adapted for longitudinal movement of approximately .O4 inches. The bottom end of pin 135, upon actuation by a temperature condition such as l35F., abuts against an upstanding button 137 carried on a transversely disposed lever arm 138 having one end provided with a flat portion 139 disposed at right angles to arm 138, said flat portion being provided with a port for loose pivotal' or fulcrum mounting of said one end about an upstanding bolt 140 adjustably secured in a boss 141 in inner housing 34. At its opposite end, arm 13S bends downwardly to provide end portion 143 (FIG. 14) whichhas a contact face 144 for engagement with the top surface of a flange on a sleeve 145 which is slidably movable about a depending tapered stud 146. The bottom end of sleeve 145 includes an internal conical countersunk end face 147 which provides an inclined surface for engagement with the top conical 'end 148 of a wobble pin 149 which extends through wobble port 114 of trigger member 112. The bottom end ofwobble pin 149 also includes a conical end 150 which is received within a tapered bore 151 in an upstanding boss 152 on the base.

It will be apparent that because of the long lever arrangement of arm 138 and the relationship of fulcrum end 139 to the button contact at 137 and to the wobble pin 149 at the other end, that a slight displacement of temperature responsive pin 135 by the bimetallic disc will cause sufficient depression of end portion 143 to depress sleeve 145 as indicated by phantom lines in FIG. 14 to cause the wobble pin to move laterally of its axis a sufficient distance to retract the trigger member 112 so that trigger engagement faces 116 and 90 disengage for release of the hammer actuating member 80 towards the hammer pin26.

Means for visibly signaling that the alarm is in unwound or partially unwound condition is generally indicated at 29 (FIGS. 4, 6 and 10) and comprises a f'lag member 160 normally disposed in a recess 161 provided in the base of the alarm when the alarm is in wound position and movable to an outwardly visible position when the alarm becomes at least partially unwound. One end portion of member 160 is secured by a screw 162 through the back wall of the base to a rocker disc 163 provided with an axial pin 164 and a smaller spaced pin 165. The pin 164 is received within a transverse slot 166 provided in end portion of member 167 connected as at 168 to the winding hub 69 and biased by a spring 170. The small pin 165 is disposed in a radial extension 171 of slot 166 and serves to orient and permit rocking of disc 163 with respect to slot 166 and the end portion of arm 167. The rocker disc 163 includes diametrically opposite projections 172 adapted to abut alternately the spaced stops 169 extending from base wall 33a.

Thus, when the spring motor is wound the hub 69 will turn through a small angle the member 167 and will cause the rocker d isc163 to be rotated clockwise as viewed in vFIGA l0 so that the end portion of arm 167 will lie against the stop 169 and one of the projects 172 will lie against the opposite lug 169 so as to retract flag member 160 into the recess in the back of the face since flag 160 is in fixed relation to disc 163. As soon as the alarm unwinds only a slight portion for any reason, such unwinding causes turning of hub 69 to turn the rocker disc to the position shown in FIG. 4 to thereby visibly display the flag member 160.

when the alarm is wound and the means for actuating the. hammer pin are in an energized start position as shown in FIG.

9 and under temperature conditions which reach the preselected actuating temperature (e.g. 135F.) of the bimetallic thermal responsive disc the alarm will commence ringing in the following manner. The bimetallic disc 131 depresses pin 135 to depress trigger member 138 to cause sleeve member 145 to move downwardly and to rock wobble pin 149 to displace the trigger member 112 by slight pivotal movement about its axis 111 so that engagement faces 116 and 90 release. Upon release of such faces, actuating member moves clockwise as shown in FIG. 4 about its pivotal axis by biasing spring 104 to move hammer face 91 toward the v sound hammer pin 26. When face 91 strikes hammer pin 26 the pin is forcibly driven toward and to strike the outer housing to sound the alarm. Upon such sharp stopping of its turning movement by contact with pin 26 the inertia disc 97 continues to pivot clockwise about its pivot axis until the face 102 strikes abutment boss 78 on the escapement lever latch 72. When this occurs the escapement latch face 74 disengages the escapement wheel tooth face 75 so that the spring motor can turn the escapement wheel. As soon as one tooth is disengaged the spring 76 biases the escapement lever 72 into engagement with the next tooth to hold the same against further rotation. The member 97 continues in its clockwise movement until the pin 101 engages the opposite side of the opening 100 and such clockwise movement is then stopped.

The actuator member 80 is returned to its start position of a hammer stroke by engagement of the hub extension 108 with an escapement wheel tooth face as at 107. When the member 80 has been turned about its pivotal axis by the turning of the escapement wheel to a location beyond trigger face 116 of trigger member 112, the contact at 107 is released so that the face will engage trigger face 116 in the event the trigger member 112 has returned to its initial position. In normal operation after the device has been set off by a temperature condition of F. or greater, the trigger member 112 is held by the thermal responsive trigger bar 138 in a retracted position so that the hammer actuator member 80 may swing by the trigger face 116 and complete another hammer stroke to ring the alarm device again. This cycle is repeated until the spring motor is completely unwound or until the device is stopped and reset.

Immediately upon turning of the spring motor upon release ofthe latching faces 74, 75, and acting through shaft 55, winding key 67, ratchet spring disc 69, arm 167, slot 171, and boss 165, arm 167 is caused to turn a slight amount to permit the spring 170 to move f'lag member 160 out of its recess 161to extend beyond the circumferential edge of the alarm device so that it may be readily viewed. The flag member remains visible until the alarm is wound to fully energized position by turning of the winding key as heretofore described.

lt will be readily apparent to those skilled in the art that the turning of the escapement wheel is incremental and the intervals between the striking of the hammer pin against the outer housing is controlled by the selected gear ratio of the gear train and the frictional resistance between the relatively mova` ble parts of the actuator mechanism.

Various modifications may be made in the hammer actuator arrangement which may come within the spirit of this invention and all such changes in the exemplary embodiment of the invention described above which come within the scope of the appendant claims are braced thereby.

We claim:

1. ln a mechanical alarm device the combination of:

a base member;

an escapement wheel mounted for rotation on said base member;

driving means for rotating said escapement wheel;

latch means on said base member for holding the drive means lto restrain rotation of the wheel;

spring biased hammer actuating means mounted on said base member for oscillatory movement;

inertia means carried on said hammer actuating means and movable relative thereto and cooperable with means on said latch means for disengagement of the latch means with the wheel at the end of a hammer actuating stroke path;

means on the hammer actuating means engagable with the escape wheel for returning the hammer actuating means to the opposite end of its stroke path;

trigger means for releasably holding the hammer actuating means in cocked position near said opposite stroke path end; and

means to release said trigger means.

. 2. An alarm device as stated in claim l wherein said means to release said trigger means includes:

a thermo-responsive bimetallic disc; and

a movable pin responsive to deflection of said disc.

3. A device as stated in claim 2 including a pivotally mounted trigger member; and a wobble pin supported by said base member and having engagement with said trigger member for displacement of said trigger member.

4. A device as stated in claim 1 wherein said trigger means includes:

a pivotally mounted trigger member; and

an externally actuatable member for releasing said trigger member for test.

5. ln a device as stated in claim l including a sound hammer pin slidably carried by said base member and having one end for strike contact with said hammer actuating means and its 7. A hammer actuator means as stated in claim 6 including a' contact face adjacent said mounting means adapted to be engaged by a t'oth'of an escapincrit means'.

8. A hammer actuating means as stated in claim 6 including an inertia member pivotally mounted on said hammer actuating member;

said inertia member including means for limiting relative movement of said inertia member with respect to said hammer actuator member:

and a strike face on said inertia member adapted to contact a latch member for release of an escapement means. 

